Such a conduit element has been known basically from DOS 3,219,360. The element comprises a self-supporting, relatively stiff corrugated exhaust gas pipe which can be denoted as being merely semiflexible. The conventional corrugated exhaust gas pipe can absorb movements perpendicularly to the axial direction only in a very limited way. This pipe has a natural resonance of above 1000 Hz lying above the customary frequencies of the systems producing the exhaust gases, such as of a motor, especially an automotive vehicle engine, with an excitation frequency of usually below 200 Hz. Excitation of the engine is evoked primarily by engine masses (pistons, connecting rods, etc.) moved by unbalanced, oscillating inertial forces. These oscillating inertial forces of the second order, responsible for excitation of the bellows, change with double the number of revolutions of the engine. The wall thicknesses of such stiff corrugated exhaust gas pipes are larger than 0.5 mm and preferably range around 1 mm hereby the high rigidity results.
Furthermore, the conventional, relatively stiff conduit element, denoted as being semiflexible, exhibits a jacket of a metallic braiding, woven material, or knit material following the contour of the waves of the corrugated pipe along the wave flanks, in order to damp the high-frequency, high-pitched, metallically clanging noises occurring due to pulsating currents when using such conduit elements in exhaust gas conduits of automotive vehicles, since, as set forth by the reference, the wave flanks are allegedly responsible, above all, for the development of noises in that these flanks begin to vibrate under the high-frequency excitation by the pulsating flow, in a similar manner as diaphragms.
These conventional conduit elements, as set forth above, exhibit high rigidity and therefore are unsuitable for the absorption and compensation of all-around movements, as they occur in such exhaust gas systems utilized particularly in motor vehicles.